First, they won't 'turn male', no worries of that. Herming is most often associated with light or heat stress.

What soil are you using? Specifically, is there peat in it?
What have you been feedin ghtem, and have you ever flushed yet?
Why are you using RO water? Is your tap water THAT bad? Are you adding CalMAg Plus (you have to if you use RO)?

Soil growers don't have to be so concerned with ppm in general, but in your case havin gthat data is useful. It sounds like you DO need to flush; do it next time your soil starts to feel dry, and flush with pH 7 water to bring up the soil pH, then feed immediately with pH 6.8 fertilizer solution mixed at half strength.
stinkyattic Reviewed by stinkyattic on . A question for Stinky My plants (grown in quality soil) are about 5 weeks old. Last week (7 days ago) I watered them with ph 6.8 RO water and gave them some nutes (@700ppm). Their runoff measured 1400ppm and the pH runoff was 6.8. I transplanted them into 1 gallon bags because they were outgrowing their container. Today I watered them with ph 6.8 RO water (no nutes) and measured their run off. The ppm was of the scale, real high and the ph read 6.0. I know my meters are accurate. I don't know how this happened but Rating: 5